عنوان مقاله [English]
In order to investigate the effect of codacide adjuvant on the efficacy of clodinafop propargyl and tribenuron methyl, a field experiment was carried out on wheat at the Iranian Research Institute of Plant Protection in Alborz province during 2013-2014 growing season. Treatments included tribenuron methyl at three doses (10.5, 12.75 and 15 g a.i. ha-1), tribenuron methyl at three doses (10.5, 12.75 and 15 g a.i. ha-1) + 0.25% V/V codacide, clodinafop propargyl at three doses (0.048, 0.064 and 0.08 L a.i. ha-1), clodinafop propargyl at three doses (0.048, 0.064 and 0.08 L a.i. ha-1) + 0.25% V/V codacide, and weed-free control. Herbicides were sprayed at tillering stage of wheat. Results showed that clodinafop propargyl at 0.08 L a.i. ha-1 performed better regarding grass weed control and application of codacide adjuvant with this herbicide increased its efficacy. Application of tribenuron methyl (12.75 g a.i. ha-1) + codacide resulted in highest reductions in broad-leaved weed density and dry matter (95% and 93%, respectively), which was not significantly different with weed-free control. Wheat biological yield (3275 kg ha-1), grain yield (2200 kg ha-1) and the number of fertile spikelets/spike (6.26) were 22, 40 and 13% higher than the weed-infested control, respectively. The lowest yield among herbicide treatments belonged to tribenuron methyl (10.5 g a.i. ha-1) with harvest index of 34.04% and 36.50 fertile spikelets/spike.